In herds of milk-producing animals such as dairy cows, the management of individuals during the transition period between lactations is very important. This is because the transition performance of an individual animal is highly influenced by health and/or disease, both of which can, in turn, be affected by management practices. The better the transition performance of an individual, the greater her overall health and productivity in the current lactation. Monitoring the transition performance of milk-producing animals is therefore of great importance to informing transition program management practices. A review of these basic concepts can be found in Kenneth V. Nordlund and Nigel B. Cook, Using herd records to monitor transition cow survival, productivity, and health (Vet. Clin. Food Anim. 20: 627-649, November 2004) hereinafter incorporated by reference in its entirety.
Currently available methods for evaluating transition performance fail to provide unbiased and objective measures of transition performance for individual animals. The ability to monitor change and to evaluate the success of innovations at a farm level remains relatively crude. Herd managers implement new transition management practices and evaluate the response within their herd using a variety of factors. Many dairies have health records to allow them to track changes in the number of disease events on their own dairy, but inconsistencies in case definition make it difficult to compare disease rates both within and between farms. Milk production monitors in early lactation are often based upon average performance of the animals that calve in a short period of time. These are easily skewed by a small number of either better or poorer animals that freshen a month earlier or later. Herd effects therefore confound the results. Other production monitors based upon first test date information are frequently confounded by variations in days in milk at first test date.
For the foregoing reasons there is a need for a method which objectively and accurately predicts an individual milk-producing animal's current milk performance based on objective measures of her own past performance and current state, and which monitors the transition programs of individuals and herds so that the health and productivity of both individuals and herds of individuals may be optimized through informed transition programs.